py2neo | comprehensive toolkit for working with Neo4j | Graph Database library

You need to define a primary key to let the MERGE know which property to use as a primary key. From the documentation:

The primary property key used for Cypher MATCH and MERGE operations. If undefined, the special value of "id" is used to hinge uniqueness on the internal node ID instead of a property. Note that this alters the behaviour of operations such as Graph.create() and Graph.merge() on GraphObject instances.

It's probably best practice to define a custom class for every node type and define the primary key there.

For now, I've solved it like this:

I have generally seen parameters used to represent values, not keys. I am not sure they can work they way you are intending.

I wonder if you might rethink your data model. If you have many values for lessonTopic in your CSV, it doesn't seem like a good choice for a relationship type. This free course might give you some inspiration. https://neo4j.com/graphacademy/training-gdm-40/enrollment/

If you really want dynamic Cypher, you can insert property keys and relationship types into the query string using Python string formatting methods, and then pass the query to graph.run().

Your code is failing because the ID for a node must be a literal (integer or string), but you set the ID as a Series when you wrote ...id = data['PMID']) . It appears py2neo allowed you to create the node object with a faulty ID, but it really shouldn't, because all relationships with that node will fail since the ID is bad.

Recreate the Node Classes with an integer for the ID, and then the Relationship between them should be created without issues.

Note, I haven't tested this code, but this is how you would loop through a df and create nodes as you go.

I guess you get this error because you're not just trying to dump the nodes and relationships, but the whole instance of the Graph class, including functions, etc.

It's not clear to me how the dump will help you achieve your goal.
This answer looks promissing though: https://stackoverflow.com/a/31809054/2403344
The idea is to create a Python iGraph from your Neo4j DB. This could then be pickled etc.

The unwind_merge_nodes_query function isn't generally intended to be used directly, although you can do so. Usually, you'd want to use the functions from the py2neo.bulk module instead, which wrap these functions.

Either way though, that nuance is unlikely to help much with your specific problems. As a client-side library, py2neo can only carry out operations exposed by the Neo4j server and, unfortunately, there exists no good (low level) way to import non-trivial bulk data from the client. Py2neo can't fix that.

If performance is your goal, your best bet might be to instead use a LOAD CSV Cypher statement. Note though that to do this, your input data file will need to be on our visible to the server directly.

There is no way to do this with the matchers. You'll have to use Cypher.

This solved the problem. I hope this will help someone in the future.

The new version 4 of py2neo is NOT requiring http but instead using bolt. I replaced all your missing modules with a working version in py2neo. See my example below;